During World War II, the Nazis looted museums and private collections then hid the plundered art and cultural artifacts in locations scattered across Germany and Austria.

Looted art was discovered in thousands of locations from castles, monasteries, military bunkers, and assorted buildings, but some of the largest repositories were inside mines.

Since the Archives of American Art’s exhibition Monuments Men: On the Front Line to Save Europe’s Art, 1942–1946 opened on February 7th there have been questions from the press and attendees about the mines—from the conditions inside to what was found at each location. These are the most frequently asked questions.

To begin with, I think it’s fair to wonder why so many mines were used as repositories. They were ideal for storing art for various reasons. At depths of up to 800 meters underground, the mines provided shelter from bombing; they were sprawling networks of tunnels capable of storing the large caches of artwork; and their interiors provided stable conditions safe from the vicissitudes of weather above ground.

The inside of the mines was cool, dark and dry. According to an Archives of American Art oral history interview with Monuments Man and conservator George Stout, who supervised the recovery of art from Merkers and Ransbach repositories, the mines were relatively dry with a low average relative humidity of 40%. This stable environment, insulated from fluctuations in temperature and humidity that damages art, in some ways matches the preferred climate–controlled conditions for document storage today: limited exposure to ultraviolet light, a constant temperature no higher than 72°F, and a steady relative humidity between 40% and 50%. Of course, there were exceptions—the climate inside Ransbach mine was considered too damp, and therefore unsuitable, for long–term storage of paintings, so it did not contain as much art as other repositories.

One complication of the art recovery effort was that many of the repositories were salt mines and airborne salinity could potentially damage uncovered paintings. George Stout described the experience of transporting art at Merkers salt mine and said the soldiers “stripped Jeeps to a size that would fit on the mine elevators and they’d take them down there to get around. Well, of course, the ground was salt, and with the jeeps running around, a certain amount of just plain salt had gone into the air.” Fortunately, most of the art and artifacts, especially Old Masters paintings, were inside wooden cases. There were nineteenth century paintings which were not housed in cases which might have been damaged by prolonged exposure to the airborne salinity but they were only there for a few weeks. Stout explained, “In paintings, that amount of salt is not a serious threat, except that it does hold moisture, and if they were moved from that locality into one of normal atmospheric conditions they would have gotten unusually damp.” Since there were no packing materials available, Stout was resourceful and used fur coats that were found in a large military store inside one of the mines to wrap and store the paintings so they were safe for transport.

In the Hollywood version of events, there is a scene inside the mines where a Monuments Man steps on a landmine hidden among some rubble and detritus. How likely was such a scenario in reality? For the most part the mines were in working condition and were actively in use by local miners who needed to have regular access to the tunnels, so the floors of the mines were not riddled with explosives.

There were some explosions in the mines used as repositories, though the blasts were not set off by accident. In Stout’s retelling of events, local miners and mine administrators at the Altaussee salt mine in Austria sabotaged the Nazis. Nazi Gauleiter August Eigruber, who was hiding in the village of Altaussee along with other SS officials and Nazi leaders, had bombs transported into the tunnels which he ordered to be detonated before the Allied troops arrived at the salt mine. In order to thwart the Nazis, “[The miners] dug up the floor of these narrow mine passages and made it that much more difficult to get through.” The miners and mine administrators saw strangers carrying oak cases into the mine each labeled Marmor, nicht stürzen (Marble, do not drop), which they found contained explosives once they inspected the contents. The bombs were placed in mine chambers but the wiring was not set up, so the miners removed them and the main entrances to the mine were blasted to deceive the Nazis and prevent further access to the looted art.

In another instance at Merkers–Kieselbach mine in Thuringia, Germany, the Monuments Men encountered a vault sealed by a steel safe door which had a combination lock that would not yield even after repeated attempts to open it. Finally, army engineers were brought to the mine and they blasted the entrance open to find a treasure trove of Nazi gold and bags of currency.

These mines were used as major repositories and famous art and objects were recovered from each. There were many different mines which stored art so this is by no means an exhaustive list, but it highlights the locations frequently mentioned in the art recovery efforts by the Monuments Men.

ALTAUSSEE salt mine (Styria, Austria) was one of the largest repositories for plundered art. The mines housed roughly 6,500 paintings as well as books, statues, furniture, and jewels from museums and private collections. Notable items include Hubert and Jan van Eyck’s Adoration of the Mystic Lamb or the Ghent Altarpiece stolen from St. Bravo Cathedral in Belgium, Michelangelo’s Madonna and Child also known as the Bruges Madonna from the Church of Our Lady in Belgium, and Johannes Vermeer’s The Art of Painting owned by the Czernin family before the war. Hitler wanted the art to become part of the permanent collection at the Führermuseum which he planned to build in Linz, Austria. The repository also contained Rothschild family jewels and Italian art from Monte Cassino for Hermann Göring’s personal collection.

BERNTERODE salt mine (Thuringia, Germany) was used to store German munitions and military supplies. The repository also contained the caskets of Prussian royalty and leaders: King Friedrich the First, Friedrich the Great, and Field Marshal Von Hindenberg and Frau Von Hindenberg. The Prussian imperial regalia, as well as treasures from Potsdam including tapestries, books, and paintings were also found within the mines.

MERKERS–KIESELBACH salt and potassium mine (Thuringia, Germany), also known as the Kaiseroda mine in the village of Merkers, housed Reichsbank gold bars worth over $200 million in 1945, bags of foreign currency, and art, including the famous Bust of Nefertiti, from several museums such as the Kaise–Friedrich Museum in Berlin and the Kusthistorisches Museum in Vienna. The mine also contained the personal belongings, jewels, and chests of gold teeth from concentration camp victims.

RANSBACH salt mine (near Merkers in Thuringia, Germany) held materials libraries sent over for safekeeping. The mine held over 2 million books, manuscripts and maps from the former Prussian State Library at Berlin, University of Marburg Library, the Landes und Stadtbibliothek of Dusseldorf, and other institutions. There were also musical scores, sheet music and stage costumes from the Berlin State Opera and Theatre and a truckload of paintings from the Berlin State Museums.

SIEGEN copper mine (Westphalia, Germany) contained a large cache of art and artifacts, notably the relics of Charlemagne from Aachen Cathedral, as well as paintings, sculpture, manuscripts, and other objects from Western German museums.

On Tuesday, March 11, at 2:30 p.m. ET we will be hosting a Twitter chat about real stories of the Monuments Men. Curators Barbara Aikens and Rihoko Ueno (@ArchivesAmerArt) will be available to answer your questions about the men and women who worked to protect Europe’s cultural heritage during World War II. Our co–hosts are the National Gallery of Art (@ngadc), the United States Holocaust Memorial Museum (@HolocaustMuseum), and the National Archives (@USNatArchives). Get your questions ready and join us on Twitter by following the hashtag #MonMenChat.

Exhibition curator Barbara Aikens will discuss highlights of the exhibition Thursday, March 13 and Friday, March 28 at 1:00 p.m. Gallery talks will be held in the Archives of American Art’s Lawrence A. Fleischman Gallery in the Donald W. Reynolds Center for American Art and Portraiture (8th and F Streets, NW).

In 1991, when I was about to be transplanted from New York to Los Angeles, a friend suggested that I read Five California Architects, Esther McCoy’s 1960s classic—an extraordinary book described by Reyner Banham as “so damned readable it was in a different league than most architectural literature.” I bought a first edition copy and was soon blithely lost in McCoy’s writing. On the book’s flyleaf, the author’s photo was an informal black and white portrait taken by Julius Shulman, a photographer famed for his hyper–cinematic depictions of mid–century modern houses. The picture of McCoy, however, was a cropped headshot set against a soft backdrop of dappled sunlight: an attractively understated woman dressed in a dark sleeveless shift, looks to one side, her lips parted as if she might be mildly amused or caught mid–conversation.

Eager to read more McCoy, my next bookstore purchase was Arts & Architecture: The Entenza Years, a 1990 anthology featuring a jazzy chartreuse and black patchwork cover, a selection of facsimile pages from this influential publication, and an essay by McCoy. This time, the author’s photograph, taken nearly 30 years later, was by Deborah Sussman, a Los Angeles–based graphic designer known for her playfully sophisticated style and monumental projects. Sussman’s portrait is casual, intimate, and precise: wearing a white dress shirt topped by a short–sleeved black sweater, McCoy gently leans into the picture, pausing between a remark and a smoke. When the New York Times published “A Chronicler of California Architecture” a 1984 profile by McCoy’s great friend and colleague Joseph Giovannini, the story opened with a photo by Sussman and a knockout description: “With her white severely cut hair, direct gaze and the ever present cigarette she holds like a pencil, the Los Angeles writer and architectural historian looks like a personality.” Although sometimes mistaken for Lillian Hellman or Georgia O’Keeffe, notes Giovannini, McCoy was in fact “very much her own figure.”

In researching McCoy’s life and work, I’ve read a wide range of her writing, both published and private, and looked at hundreds of photographs, images that span most of the 20th century. Photographs from McCoy’s childhood—she was born in 1904 and grew up in Coffeyville, Kansas—convey Edwardian era home comforts, stout bungalows and new automobiles, in the American Midwest.

In one schoolgirl portrait, McCoy, posed against flowered wallpaper by a curtained window, sports Sunday best—a dress with a middy collar and knife pleat skirt, an enormous hair bow, and a thoughtful but somewhat skeptical expression.

By the time she was 21, McCoy had arrived in Greenwich Village to pursue life as a writer. Her fashion sense had become pared down, deliberate, and Jazz Age–appropriate but her expression remained remarkably unchanged. In an unpublished memoir, she considered her 1927 passport picture and wrote:

…straight brows, straight gaze and almost straight lips. I look unrelentingly into the camera lens, as if it were the fate I well knew I deserved…I see no more than the V–necked blouse of a two piece jersey dress, and it recalls to me that I began wearing knits long before they were popular, and long before ways had been found to keep the sag out of the seat.

Photographs of McCoy deliver telling glimpses of both her individual biography and a larger view of a thoroughly modern woman living on the progressive edge of the 20th century. Over the course of seven decades, from that first passport photo to Sussman’s urbane snapshots, McCoy always appears bracingly contemporary, straightforward, and bright: in the 1930s, she’s pictured holding her signature cigarette, dressed in a striped T shirt, swimsuit, and white sneakers, outside a Southern California dune shack; in the 1940s, walking down the street of her hometown, she is Katharine Hepburn–like in trousers and a well–tailored jacket; and in the 1950s, standing at the top of the stairs at Casa Barragan in Mexico City, her silhouette in a simple blouse and full–skirt is framed by the sharp geometry of the architectural space.

As someone who never met McCoy, I “know” her entirely through images, words, and anecdotes. Reading architect Michael McDonough’s 1989 appreciation, “First Lady of L.A. Architecture” in Metropolitan Home, I found the accompanying photograph disconcerting. McCoy, who had indeed been employed as a draftsman during the 1940s, is posed at a pristine, graphite–free drawing board. Her hair is coiffed, crimped into waves, and her sharply pressed white blouse is uncharacteristically fussy. I thought there was something wrong with this picture. Photographed by Maynard L. Parker in 1946 or ‘47, it’s an oddly staid composition, more reminiscent of early 19th century neoclassical painting than postwar Los Angeles: a pensive woman at an easel, seated before a large window, is gently illuminated by daylight.

A prolific photographer, Parker was a favorite at House Beautiful and a regular contributor to other mid–century home design magazines. When his McCoy portrait, one of the first images from the McCoy papers at the Archives of American Art to be individually digitized, appeared on–line it became popular with a new generation of magazine art directors and editors.

Each time I saw the photograph reproduced, I felt uneasy. I could recognize McCoy but I was always reminded of something else, an image out of a more distant past—a painting in the Metropolitan Museum of Art, The Young Woman Drawing (1801) by Marie–Denise Lemoine Villers—formerly misattributed as a portrait of Charlotte du Val d’Ognes by Jacques–Louis David. The staginess of the Parker portrait seemed to represent a picturesque idea of a lady artist at work rather than a portrait of an actual woman.

Parker’s archive of “approximately 58,000 negatives, transparencies, and photographs” is housed at The Huntington Library. In the summer of 2009, responding to a query I’d sent regarding an article featuring Parker images in an out–of–print magazine, I received an email from Jenny Watts, the Huntington’s Curator of Photographs: “Re: the picture from Mademoiselle (George Turner residence in La Canada)—this is one of my favorite photo shoots in the collection as it gives a wonderfully complete picture of middle class modernism from the period…” she wrote, providing links for the collection’s newly scanned images. “I’m assuming the woman is the architect, but I’d like to know who.”

In Parker’s theatrically–lit and highly staged scenes of sun–kissed domestic bliss, models were hired to portray can–do dads tending the barbecue, happy moms carrying the birthday cake, and children merrily gathering ‘round the Christmas tree. Of course, when I clicked on the link, I discovered that the earnest architect in the Turner house photo shoot—carefully styled and posed at her drawing board—was being played Esther McCoy.

Susan Morgan has written extensively about art, design, and cultural biography. A former contributing editor for Interview, Mirabella, and Metropolitan Home, she is a contributing editor for Aperture and www.eastofborneo.org, the collaborative online art journal and archive. With support from the Graham Foundation, the Beverly Willis Architecture Foundation, the Smithsonian Institution, and the NEH, Morgan has been researching the life and work of writer Esther McCoy. She is editor of Piecing Together Los Angeles: An Esther McCoy Reader (2012), the first McCoy anthology, and co-curator (with Kimberli Meyer) of Sympathetic Seeing (2011), for the MAK Center at the R. M. Schindler House, West Hollywood, CA.